The U.S. Supreme Court on Thursday banned the use of race and ethnicity in university admissions, overturning a decades-old practice that boosted educational opportunities for African-Americans and other minorities.

U.S. President Joe Biden said he "strongly" disagreed with the ruling, which "walked away from decades of precedent," adding that universities "should not abandon their commitment" to create diverse student bodies.

"Discrimination still exists in America," said Biden. "Today's decision does not change that. It's a simple fact that if a student has had to overcome adversity on their path to education, colleges should recognize and value that."

"I believe our colleges are stronger when they are racially diverse... We cannot let this decision be the last word."

The justices broke six to three along conservative-liberal lines in the decision, which came after years of ring-wing antipathy to "affirmative action" programs that have sought diversity in school admissions and business and government hiring. Chief Justice John Roberts wrote in the majority opinion that while affirmative action was "well-intentioned and implemented in good faith," it cannot last forever, and amounted to unconstitutional discrimination against others.

"The student must be treated based on his or her experiences as an individual - not on the basis of race," Roberts wrote. 

The court sided with an activist group, Students for Fair Admissions, that sued the oldest private and public institutions of higher education in the country - elite Harvard University and the University of North Carolina (UNC) - over their admissions policies. The group claimed that race-conscious admissions policies discriminated against equally or better-qualified Asian Americans competing to enter the two universities.

Conservative politicians welcomed the decision. 

"This is a great day for America," said ex-president Donald Trump, who helped build the court's conservative majority with three appointments.

It "will make the college admissions process fairer and uphold equality under the law," added Republican U.S. House Speaker Kevin McCarthy.